Question

Write the balanced chemical equations for the following reactions-

(a) Sodium carbonate on reaction with hydrochloric acid in equal molar concentration gives sodium chloride and sodium hydrogen carbonate.

(b) Sodium hydrogen carbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide.

(c) Copper sulphate on treatment with potassium iodide precipitates cuprous iodide $\left({\text{Cu}}_2{\text{I}}_2\right)$, liberates iodine gas and also forms potassium sulphate.

Answer 1

Part (a):

Sodium carbonate$\left(N{a}_{2}C{O}_3\right)$ on reaction with hydrochloric acid$\left(HCl\right)$ in equal molar concentration gives sodium chloride$\left(NaCl\right)$ and sodium hydrogen carbonate$\left(NaHC{O}_3\right)$.

${\text{Na}}_2{\text{CO}}_3+\text{HCl}\to \text{NaCl}+{\text{NaHCO}}_3$

Part (b):

Sodium hydrogen carbonate$\left(NaHC{O}_3\right)$ on reaction with hydrochloric acid$\left(HCl\right)$ gives sodium chloride$\left(NaCl\right)$, water$\left(H_{2}O\right)$ and liberates carbon dioxide$\left(C{O}_2\right)$.

${\text{NaHCO}}_3+\text{HCl}\to \text{NaCl}+{\text{H}}_2\text{O}+{\text{CO}}_2$

Part (c):

Copper sulphate$\left(CuS{O}_4\right)$ on treatment with potassium iodide$\left(KI\right)$ precipitates cuprous iodide$\left(C{u}_2{I}_2\right)$, liberates iodine gas$\left(I_2\right)$, and also forms potassium sulphate$\left(K_{2}S{O}_4\right)$.

$2{\text{CuSO}}_4+4\text{KI}\to {\text{Cu}}_2{\text{I}}_2+2{\text{K}}_2{\text{SO}}_4+{\text{I}}_2$